Portable Generators Buyer's Guide
Back-up generators are called upon when a storm or accidental damage to a utility interrupts the flow of electricity to a home, business or institution. The electricity might be needed to power life-support systems in a rest home, to keep critical ventilation fans operating in a confined livestock operation, or to restore security at a critical transportation center. Non-emergency generator uses include providing supplemental juice for scheduled public events held in areas off the electrical grid such as ad hoc concerts in open fields.
Like any other product, these portable auxiliary power units vary in quality and price. Thoroughly explore options because good deals are not always immediately evident. Some things to consider:
Shop Brands
Manufacturers of generator units are numerous and established. Global names like Doosan Portable Power and Generac immediately come to mind. While start-up brands and niche manufacturers always are worth a look, decades of manufacturing excellence generally are proof of quality. When in the market for tow-behind power , remember that reliable performance should trump price when emergency work or uninterrupted production is the goal.
Heed Service Agreements
Almost as important as reputation are manufacturer warranties and dealership support. Generators that fail or inexplicably shut down can bring havoc to a public event or disrupt an emergency response. When machines fail — anything mechanical occasionally does — the written pledge of a dealership or manufacturer to respond immediately with a replacement unit is a value that’s hard to put a price tag on.
Where to Buy
Buyers have several ways to acquire one of these towable machines. Some manufacturers offer direct factory sales, which eliminates costs associated with purchasing through a dealership. On the other hand, the proximity of a dealership can be important for product support. Second-hand generators can be found at brick-and-mortar stores as well as online. Auctions are yet another source for second-hand equipment, with some auction houses specializing in government surplus units. Caution: Online buyers should pay attention to stipulated limits on the condition of equipment.
Many reputable rental companies, national and local, carry these portable pieces of equipment in their inventory, usually stocking market-leading brands. Two general rules of thumb:
Shop Size and Capacity
Manufacturers offer auxiliary support equipment in a wide range of outputs. While you know your needs better than anyone, an experienced rental or leasing agent can match your need to a particular piece of equipment. While you may not know thow many kilowatts of electricity are required to power your equipment, the experts should be able to tell you.
Understand the Agreement
The terms of service in a rental document protect you and the rental company. On the company side, the renter is accountable for any abuse or neglect of a rented machine and for returning the machine to the store by a stipulated date. Essentially, the renter must care for the machine so that it is returned promptly and in the same condition as when it left the lot. For the renter, the agreement ensures that the piece of equipment will function as promised and that, if it doesn’t, a replacement machine will be provided at no additional cost. Read the fine print for peace of mind.
In a global market, the price for an auxiliary power unit varies by region. The more widely you explore the market, the broader your options are apt to be. Following are some advertised samples of pricing:
New Towable Generators
11 kW — CK Power single-axle version of the Kubota Lowboy II GL11000 generator … front and rear leveling jacks … $14,300.
25 kW — Generac MDG25IF4 three-phase generator on a single-axle trailer … four-cylinder Isuzu Tier IV Final diesel engine … $25,000.
83 kW — Doosan Portable Power 5WCU generator … 126-hp. Cummins diesel engine with a 189-gal. fuel tank … tandem axle… $52,000.
Used Towable Generators
Second-hand equipment is a good investment if attention is paid to condition and to a particular model’s track record of performance. Some shine might be gone from the paint, but the underlying mechanics can have years of dependable service in them. Following is a sampling of advertised prices:
21 kW … 2013 Ingersoll Rand G25 … 32-hp. diesel engine with 9,000 hours … single-axle trailer … $15,000.
50 kW … 2004 Kohler 60REOZJB unit … dual-axle trailer … 70 hp. John Deere 4045 diesel engine … $12,000.
150 kW… 2014 Magnum MGG200 generator … six-cylinder Generac natural gas engine … 6,000-lb. dual axles … $79,000.
Rental Or Leasing Costs
Rental markets vary so widely between rural and urban regions and different economic areas that price generalizations are hardly conclusive. Suggested rental/lease rates are just that — suggestions. With that caveat, following are some ballpark rental prices:
20-40 kW generators: $200 a day, $550 a week, $1,700 a month
175 kW generators: $400 a day, $1,500 a week, $3,500 a month
Some Purchase Options
Buying a towable auxiliary power unit can be a substantial investment. When a buyer is a new contractor or a property owner, funding the purchase can be problematic. Equipment dealers and second-hand stores understand this and offer a variety of ways for buyers to finance the needed power units. Some dealers offer lease agreements with an option to buy, sometimes at rates lower than traditional financing. Others charge no interest on a credit card purchase if the full amount is paid off in 18 months. Supply and demand ultimately determine financing costs.
Kilowatts produced
Wattage is the measurement of electrical power. A kilowatt is one thousand watts and is the measure of generator output. A towable generator should produce enough kilowatts (kW) to fully energize the equipment or installation to which it is connected. That is, a generator must have a kW rating equal to the task. Generator engines (usually diesel) scale up in models to produce necessary kilowatts.
Fuel capacity/running time
Work days on remote job sites are interrupted when generators quit running. Even more important, generators powering critical public facilities, such as hospitals, must be able to run more or less continuously during emergencies. So, an auxiliary generator should have a fuel tank large enough to keep the machine outputting electricity hour after hour after hour.
Size/weight
A 14 kW tow-behind generator rolls on a single axle and can weigh 1,400 lbs. A 65 kW unit might weigh more than 5,000 lbs. distributed across two axles. It follows that a property owner wanting to generate electricity for a weekend soiree in his pasture can pull home the small generator with an SUV, but the big unit will require a truck.
Doosan Portable Power
Reputed to be the oldest South Korean company, Doosan is a conglomerate with industrial products ranging from towable generators to heavy construction machines. In 2007, it acquired Bobcat, a global leader in the manufacture of skid steers. Click here to see Portable Generators currently for sale from Doosan Portable Power →
Generac
This Wisconsin manufacturer dates from 1959. Its product line ranges from portable generators to huge nine-megawatt plants. It was a global leader in the introduction of telescopic mast towers and LED auxiliary lighting lamps. Click here to see Portable Generators currently for sale from Generac →
Portable Generators are not acquired on a whim. Genuine need drives the purchase or rental of such equipment — emergencies, urgent maintenance work, and expansion of a work project into a 24/7 operation. The good news is that manufacturers have a full line of equipment for such time-sensitive situations, so a need can be met quickly.
